Originally the sidekick to Radioactive Man in the Radioactive Man comic series on the Simpsons. In the film version of Radioactive Man (starring Ranier Wolfcastle) Milhouse was cast in the role of Fallout Boy.

Bart: Well, between us we've read all 814 issues of "Radioactive Man."

Milhouse: Yeah, and we both have the special limited-edition issue where he and Fall out Boy get killed on every page!

1. A Chicago-based band whose sound is characterized by crunchy metallic riffs and by stop-start rhythms, as well as sometimes cheeky, sometimes emotional lyrics.

Could be (and often is) described as part of the modern pop-punk emo movement, though it has to be noted they are far more rock-oriented and electrically charged than self-admittedly emo bands such as Dashboard Confessional.

Started out fairly indie but has since gained a huge mainstream "pop" audience.

For those of you who think Fall Out Boy are emoposers; they aren't. They aren't even emo, and, like I said, had a life before MTV. It's MTV that made them so popular, along with some air headed teenage girls, who only listen to them because 'PeTe Iz SoOoOoO hAwT!!!!!11'.

Oh, and by the way, there is no 'Tom' in Fall Out Boy. On the From Under The Cork Tree album, some tracks were mixed by Tom Lord-Alge, which could be the cause of this misconception of the invisible 'Tom'.

Air Head : OMG, LIEK PETE FROM FALL OUT BOY IZ SOOO HAWT!!!!!1
Normal person : Air is leaking out.

A band from chicago formed around 2001. It consists of pete Wentz, Patrick Stump, Andrew Hurley, Joe Trohman. They are not I REAPEAT NOT, and emo band(see the get up kids for some). If anything someone could call them Pop-punk. In my opinion a very good band who's fans actually go deeper than what most of you think. Fall Out Boy did exist before they were on TRL, therefore their fans existed before TRL and thefore do not consist only of 13 year old girls who love guys in gril pants.

Catchy guitar riffs and unique vocals make their music better than anything you and your crappy yamaha bass could put out.

Urban dictiony person:Fall Out Boy is SOOOO Emo.
Actual intelligent Fall Out Boy Fan:You Fucking Idiot, no they aren't, listen to the lyrics you dumbfuck.

A band, not a "gay shitty ass emo band", a band. That's what some of you guys keep on posting that and we all get it, you don't like them, they may not be worthy of your time, but they do deserve your respect. And you go far enough by saying "all their fans are retarded emo faggots" when you don't even know who half of them are. Just because people like them, doesn't mean they're all "emo", "retarded" or "homosexual."

person 1: Fall Out Boy sucks ass! They're such gay, emo faggots and their fans are retarded!
person 2: Shut the fuck up, all you ever talk about is how much Fall Out Boy "sucks" Gosh, they're just a fucking band, Why waste your life complaining about it, Quit being so bigoted!!!!!!!!!!!!

The name is derived from the television show, The Simpsons, Fallout Boy is the young sidekick to the Superhero, Radioactive Man. Like Robin is to Batman.

The band Fall Out Boy is currently(2005-06) very popular. However, they give what is quite possibly the worst live performance of any major record label band currently out.

The guitarist and bassist insist on being in constant motion while on stage, including jumping in 360's, getting on top of amps, and jumping off of stage platforms, even though they are physically incapable of continuing to play correctly while doing so. The lead singer/second guitarist can neither sing, nor play guitar well, much less perform both tasks at the same time. This produces a stage sound and presence which is highly unnatractive, and very unpleasant to the ear.

Their songs are pop-driven, somewhat simple, yet varied, and feature many catch phrases that will be branded all over your friends' AIM profiles and Myspaces for the next few months.

Examples:

"Drop a heart, break a name"

"I'm just a notch in your bedpost, but you're just a line in this song"

"Sugar, we're going down"

"We'r always siffee ee eida sefehh fodah roongg teeee"

As the last quote demonstrates, most of their lyrics, even on the studio tracks, are indiscernible to the common person's ear. But not the 8th and 9th grade girls. They can mysteriously hear all of the lyrics and find great, deep meanings in them.

1: Fall Out Boy are a band from Chicago, made up of four members... Peter Wentz, Patrick Stump, Andrew Hurley and Joe Trohman. Due to certain lines in the songs, they are considered EMO (by people who need to be shot), but they are actually NOT. They are critised alot for Patrick Stump's lead vocals, apparently, being "horrible" and "hard to understand". The answer to this is, of course, get your fucking ears cleaned out because if TONS of people can hear what the hell he says, why cant YOU?

2: A fact that is NOT known to many people, is that Fall Out Boy actually had a LIFE before MTV. And It was not up to the band to have hundreds of stupid airheaded girls constantly asking for their music videos to be played on MTV due to the fact that "Peter is so HAWT!!!" If you are going to blame somebody in that situation, blame MTV. Or better, the stupid airheaded girls.